We now have the beer in the fermenter and ready for fermentation and storage under controlled conditions.
To make great beer we need to control our fermentation time and temperature profile.
The beer and in particular lager needs periods of time when their temperature need to be above ambient and times when it needs to be below ambient.
Heating the Fermenter
The simplest way is to use a brew belt or heating pad
Local HB Shop
These can be used stand alone or with a STC-1000 type controller: www.buyincoins.com/new_en/details/220v-digital-lcd-thermostat-temperature-regulator-controller-aquarium-fish-tank-product-12371.html
Cooling the Fermenter
This is more difficult!
In order to automate the cooling people use a fridge or a freezer.
These are connected to the affore mentioned STC-1000 controller.
Fit the fermenter with a brewbelt or the like then you have total control of your fermentation